Ferguson joins the Lions following two seasons (2014-15) with the Chicago Bears after entering the League as a second-round pick (51st overall) by the Bears in the 2014 NFL Draft out of Louisiana State. He has appeared in 20 games with one start, and his career totals include 25 tackles (12 solo) and two sacks.

Gaston comes to Detroit in his third season after most recently spending time as a member of the Carolina Panthers practice squad in 2016. Prior to Carolina, he played with both the Chicago Bears (seven games) and Green Bay Packers (two games) in 2015. Gaston entered the NFL in 2014 when he signed with the Arizona Cardinals as an undrafted rookie free agent of out Purdue, and his career totals include 12 total tackles and one sack.